Twenty-First Century Fox Inc.'s (FOXA) London offices were raided by investigators from the European Commission over potential abuse of its dominant position in broadcasting of major sporting events.

Fox confirmed the raids and said that Fox Networks Group, a unit that distributes TV and cable channels, and content around the world, was cooperating with the investigation.

Documents and computer records were reportedly taken in the raid, which was prompted by concerns by the EC that Fox "may have violated EU antitrust rules that prohibit cartels and restrictive business practices."

The EC, the executive branch of the European Union, confirmed on Tuesday it had performed "unannounced inspections" at the offices of unnamed companies in several EU countries.

"The European commission can confirm that on 10 April its officials carried out unannounced inspections in several member states at the premises of companies active in the distribution of media rights and related rights pertaining to various sports events and/or their broadcasting. Unannounced inspections are a preliminary step into suspected anticompetitive practices," a commission spokesman said on Tuesday.

Fox shares were down 0.74% in premarket at $36, after gaining 1.6% to close at $36.27.

Fox is awaiting the outcome of an investigation by Britain's antitrust regulator over the its proposed acquisition of the 61% of Sky plc (SKYAY) it doesn't already own, which was first launched in December 2016.

In January, the Competition and Markets Authority the decision to provisionally block the deal the impact the purchase would have on "media plurality" in the U.K., given the dominance Fox would have over the domestic media landscape and the fact that Murdoch Family Trust assets are watched and read by a third of the population, and the influence it would have over the Sky News channel.

In a bid to gain approval Fox has offered to ringfence Sky News. Fox also said that the Walt Disney Co. (DIS - Get Report) has expressed interest in buying the news channel, whether or not Disney's proposed $66 billion acquisition of Fox's entertainment assets proceeds.

The CMA will make its final decision about the Sky takeover, with a report submitted to the Secretary of State by May 1.

Sky shares were down 0.57% on Wednesday, changing hands at 1,319 pence.